Leakage current sensor and leakage current monitoring device

Abstract

A leakage current sensor and a leakage current monitoring device; the leakage current center comprising an input end, an output end and an ASIC chip; the ASIC chip is electrically connected with the input end for reading analog quantity signals of the input end; the ASIC chip is further electrically connected to a digital signal processing module; the digital signal processing module can output digital quantity signals to the output end; the digital signal processing module can simultaneously feedback the output digital quantity signals to the ASIC chip, thereby forming a closed-loop feedback circuit; the input end of the leakage current sensor comprises a current sampling unit; a reference unit is arranged between the current sampling unit and the ASIC chip.

The invention claimed is: 
     
       1. A leakage current sensor, comprising:
 an input end, 
 an output end, and 
 an ASIC chip, wherein the ASIC chip is electrically connected with the input end for reading analog quantity signals of the input end, wherein the ASIC chip is further electrically connected to a digital signal processing module, wherein the digital signal processing module can output digital quantity signals to the output end, wherein the digital signal processing module can simultaneously feedback the output digital quantity signals to the ASIC chip, thereby forming a closed-loop feedback circuit, wherein the input end of the leakage current sensor comprises a current sampling unit, wherein a reference unit is arranged between the current sampling unit and the ASIC chip, wherein the ASIC chip controls the reference unit to generate reference currents with different grades, wherein the current sampling unit is used for sampling and acquiring the analog quantity of the reference current or the leakage current, wherein the ASIC chip repeatedly sets a same reference current value for calibration, and reads the digital quantity signals fed back by the digital signal processing module, thereby forming the corresponding mapping between the analog quantity and the digital quantity of the reference current. 
 
     
     
       2. The leakage current sensor of  claim 1 , wherein the ASIC chip compensates the errors of the analog quantity signals of the leakage current according to aforesaid corresponding mapping, thereby outputting digital quantity signals. 
     
     
       3. The leakage current sensor of  claim 2 , wherein the ASIC chip has a preset programmable circuit, which can programmatically achieve the gain output of the digital quantity signals. 
     
     
       4. The leakage current sensor of  claim 3 , wherein the communication module reads the state signals sent by the ASIC chip and further forwards the signals to an external device, thereby achieving a bidirectional signal communication. 
     
     
       5. The leakage current sensor of  claim 1 , wherein the ASIC chip has a preset programmable circuit, which can programmatically achieve the gain output of the digital quantity signals. 
     
     
       6. The leakage current sensor of  claim 5 , wherein the leakage current sensor further comprises a communication module, and the ASIC chip is electrically connected with the communication module, wherein the communication module is connected with an external device for acquiring external control signals, wherein the ASIC chip reads the aforesaid external control signals and adjusts the programmable circuit. 
     
     
       7. The leakage current sensor of  claim 1 , wherein the leakage current sensor further comprises a communication module, and the ASIC chip is electrically connected with the communication module, wherein the communication module is connected with an external device for acquiring external control signals, wherein the ASIC chip reads the aforesaid external control signals. 
     
     
       8. The leakage current sensor of  claim 1 , wherein the leakage current sensor further comprises a safety self-checking module and an over-temperature protection module, wherein the safety self-checking module and the over-temperature protection module are respectively electrically connected with the ASIC chip, wherein the over-temperature protection module has a preset temperature upper limit. 
     
     
       9. The leakage current monitoring device of  claim 8 , wherein the annular magnetic core is made from an amorphous strip material. 
     
     
       10. A leakage current monitoring device, comprising: the leakage current sensor of  claim 1 , a base plate, and an annular magnetic core that is fixedly connected with the base plate, wherein the base plate is embedded in an outer shell, and the leakage current sensor is embedded in the base plate, wherein a peripheral circuit and a plurality of lead feet are arranged on the periphery of the leakage current sensor, wherein the lead feet are led from the peripheral circuit, and are further connected with an external device, wherein the leakage current monitoring device comprises at least one bus bar, which is led from a monitored leakage current component, and penetrates through the annular magnetic core.